Evidence For Evolution: Analysis A Fair Look at the Evidence for and Against Evolution

The Nature of Science Methodological vs. Metaphysical Naturalism Why Methodological Naturalism? 1. It Works! 2. Denying it Breaks the Scientific Method

Problems with Methodological Naturalism The History of Science Limits Possible Explanations Design Explanations Used Elsewhere in Science 1. Archaeology 2. SETI

Methodological Naturalism and Intelligent Design Intelligent Design is Compatible with Methodological Naturalism.

The Nature of Science Three Criteria 1. Methodological Naturalism 2. Falsification 3. Predictability

Falsification and Predictability Questionable as Necessary Preconditions Intelligent Design and Creationism Do Make Predictions and are Falsifiable Is Evolution Falsifiable?

Falsification and Predictability Allen Orr “Indeed, because the very act of revising a program has a way of wiping out clues to its history, it may be impossible to reconstruct the path taken. Similarly, we have no guarantee that we can reconstruct the history of a biochemical pathway. But even if we can’t, its irreducible complexity cannot count against its gradual evolution any more than the irreducible complexity of a program does—which is to say, not at all.”

Science Vs. Religion? NOMA -> Non-Overlapping Magisterium the magisterium of science covers the empirical realm: what the Universe is made of (fact) and why does it work in this way (theory). The magisterium of religion extends over questions of ultimate meaning and moral value. These two magisteria do not overlap, nor do they encompass all inquiry (consider, for example, the magisterium of art and the meaning of beauty).

Problems with NOMA Certain Religions Make Claims that May Have an Impact on the Physical Universe. With “NOMA,” Gould Gives Science Realm over “Facts,” Making Religion Irrelevant to Reality. History of Science: Integration of Science and Faith.

Understanding Evolutionary Theory Two Key Propositions: 1. Common Descent 2. Random, Unguided Processes as Mechanism

Understanding Evolutionary Theory Two Key Concepts: 1. Micro-Evolution Based on Observed Data 2. Macro-Evolution Based on Inference and/or Speculation Due to the very nature of Darwinian Evolution (slow, gradual process) - We Have no Direct Observational Evidence for Macro-Evolution

Evolution + Christianity? Christianity is (logically) consistent with common descent. Christianity is not consistent with unguided, random processes as sole mechanism.

Evidence for Evolution 1. Experimental Evidence 2. The Fossil Record 3. Biology 4. Genetics

1.) Experimental Evidence: Counterpoint Evidence for the Neo-Darwinian Mechanisms Evidence for Speciation 1. Definition of Species 2. Speciation Events: Macro or Micro Evolution?

2.) Fossil Evidence: Counterpoint Geological Column - Ordering of the fossil record into distinct periods. Different ranges of time are associated with particular strata of rocks. Cambrian Explosion Almost all major phyla appear in fossil record.

2.) Fossil Evidence: Counterpoint Niles Eldredge -> Punctuated Equilibrium (1989) Most families, orders, classes, and phyla appear rather suddenly in the fossil record, often without anatomically intermediate forms smoothly interlinking evolutionarily derived descendant taxa with their presumed ancestors. Cambrian Explosion > A Powerful but not Unique Example

2.) Fossil Evidence: Counterpoint Archaeopteryx Tiktaalik "Previous data from another ancient fish called Tiktaalik showed distal radials as well -- although the quality of that specimen was poor. And the orientation of the radials did not seem to match the way modern fingers and toes radiate from a joint, parallel to each other." Homo Erectus

3.) Biological Evidence: Counterpoint Homology Homology - Any similarity between characteristics that is due to shared ancestry. What About Shared Design? Chevy and Ford: Common Ancestor or Common Designer?

3.) Biological Evidence: Counterpoint Vestigial Structures Vestigial Structures - Homologous characters of organisms which have seemingly lost all or most of their original function in a species through evolution. 1.Often have a function ( organs.html) organs.html As we learn more, we discover more functions “Vestigial” Organs in humans in 1890: 180 “Vestigial” Organs in humans in 1999: 0 What about the Fall? Homo Erectus

4.) Genetic Evidence: Counterpoint Comparative Sequencing 1.Often Leads to Inconsistent Results Pseudogenes 1.Often are found to have function. Hirotsune's report prompted two molecular biologists to carefully review scientific literature on the subject of pseudogenes. To the surprise of many, they found a number of examples in which pseudogenes play a role in gene regulation and expression,[20] forcing Hirotsune's group to rescind their claim that they were the first to identify pseudogene function.

Intelligent Design? Michael Behe -> Darwin’s Black Box Irreducible Complexity - A system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning.

Evolutionary Evidence: Strengths Geological Column lends some credence to common descent. Genetic evidence of pseudogenes is easier to understand via an evolutionary model than a creation model. The mechanisms (mutation, natural selection), are well established.

Evolutionary Evidence: Weaknesses Very little evidence for the “randomness” thesis, even if common descent is affirmed. Fossil evidence is shaky. Often lacking rigorous explanations of how certain structures involved -> propensity towards “hand-waving.” Does not fare well given recent discoveries of amazing complexity in the cell/living organisms.

Conclusion Some facets of evolutionary theory have evidential backing, but when we have a clear understanding of the theory and make some important distinctions, and analyze the evidence fairly, we realize that many of its conclusions are speculative at best.

Questions?